Bubbles beautify your aquarium display, improve water quality, and make it more hospitable for aquarium inhabitants. In addition to providing oxygen for fish to breathe, aeration devices play a vital role in maintaining efficient biological filtration.

Oxygen and biological filtration
Aquarium biological filtration relies primarily on aerobic beneficial bacteria to break down nitrogenous waste materials. Without a steady supply of fresh oxygen, harmful gasses and chemicals can quickly accumulate to create a toxic environment. A sudden buildup of excess waste materials can then trigger a series of events to further exacerbate the situation.

Beneficial bacteria reproduce rapidly in response to sudden increase in waste materials (for example, due to overfeeding). As they multiply, the bacteria become visible and form what look like clouds of swirling, white smoke. This bacteria bloom uses up large amounts of oxygen and can create an oxygen-poor environment harmful to fish and other inhabitants.

Increase oxygen
Water with low oxygen content is more common and dangerous to aquarium inhabitants than often realized. Fortunately, the use of
aeration devices like
air pumps and
airstones are an easy and effective way to replenish and maintain healthy oxygen levels.

A constant supply of fresh oxygen allows efficient
biological filtration to take place without depleting oxygen fish need to breathe.
Aeration devices also promote proper gas exchange and reduce buildup of harmful gasses such as carbon dioxide. They also maintain a stable pH by counteracting the pH-lowering effects of carbon dioxide.